My 10-Year Challenge - WriteableBitmapEx turns 10 with v1.6

It was 2009 when I started my first open source project and announced it with this unspectacular blog post. Back then it was developed with Visual Studio 2008 targeting Silverlight and hosted on CodePlex.
Many things have changed and tech comes and goes but during the last 10 years I always adapted, extended it, added bug fixes and reviewed/merged Pull Requests. Even after all the years WriteableBitmapEx is still quite popular, especially with Windows desktop WPF developers.

Version 1.6.2 of WriteableBitmapEx finally adds dedicated libs for UWP and an UWP sample. For WPF it now supports .NET Core, both the .NET Framework and .NET Core libs are part of the NuGet pack.

If you are using the source code and the VS solution directly, you can choose the .NET Framework 4.5 or .NET Core 3 as the target in the VS drop-down.

WriteableBitmapEx supports a variety of Windows platforms and versions.
WPF and Windows 10 Universal Windows Platform (UWP) are actively maintained.
Silverlight, Windows 8/8.1 WinRT, Windows Phone WinRT and Silverlight 7/8/8.1 are not maintained anymore but the latest stable libs are still part of the NuGet package.

You can download the latest via the updated NuGet package. The packages contain the WriteableBitmapEx binaries. All samples and the source code can be found in the GitHub repository.

A huge shout out and thank you to all the contributors, bug issuers and users of the library. ❤

Long time no hear - WriteableBitmapEx 1.5.1 is out

Even after all the years WriteableBitmapEx is still quite popular, especially with WPF developers and I always incorporate bug fixes and also accept Pull Requests if I get some time.
Many contributions were integrated and lots of bugs fixed. Among those are some nice additions like a clipped line drawing or a dotted line renderer.

WriteableBitmapEx supports a variety of Windows platforms and versions: WPF, Silverlight, Windows 10 Universal Windows Platform (UWP), Windows 8/8.1, Windows Phone WinRT and Silverlight 7/8/8.1.

You can download the latest via the updated NuGet package. The packages contain the WriteableBitmapEx binaries. All samples and the source code can be found in the GitHub repository.

A big thank you to all the contributors, bug reporters and users of the library who help with feedback.

IdentityMine Post - Client-side caching matters

I was recently part of a project at IdentityMine where worked on a Xamarin application for the Amazon Fire TV Android platform. We faced some challenges which we love to address. One of which was the backend speed; however, this feature was out of our scope. Still, the client application needed to interact with the backend speed. Otherwise, with no data, there is no application.

I wrote a post about the learning experiences for the IdentityMine blog. If you are interested in client side development you might want to read it.

We've Come a Long Way Baby - WriteableBitmapEx now on GitHub

The WriteableBitmapEx project is now 6 years old and times have changed since all began. It all started with Silverlight and more XAML flavors were added over time until all XAML flavors were supported including Windows Phone, WPF, WinRT Windows Store XAML, (Windows 10) UWP and still Silverlight.

The version control system and open source services landscape has changed as well and the CodePlex infrastructure has not been too reliable recently. That's why I finally took the time to move the WriteableBitmapEx source code from CodePlex' SVN bridge to Git and make it available on GitHub: https://github.com/teichgraf/WriteableBitmapEx
Additionally was the open source license changed from Ms-PL to MIT which should simplify the usage as well. See the Codeplex Issue Tracker for a list of features that will be added in the future. Please use the GitHub Issues functionality to add new issues which are not already reported. Of course the latest binaries will continue to be distributed via NuGet.

Staying Alive! - WriteableBitmapEx 1.5 is out

After a couple of minor updates on top of version 1.0 which lead to 1.0.14, I'm happy to announce that WriteableBitmapEx 1.5 is now available.
Many contributions were integrated and lots of bugs fixed. Among those are some nice new color modifications and also long awaited DrawLine with variable thickness, pen support, better anti-aliased lines, Cohen-Sutherland line clipping, even-odd polygon filling and alpha-blended shape filling... Read the details at the end of this post or the release notes.

WriteableBitmapEx supports a variety of Windows platforms and versions: WPF, Silverlight, Windows 10 Universal App Platform (UAP), Windows 8/8.1, Windows Phone WinRT and Silverlight 7/8/8.1.


You can download the binaries here or via the NuGet package. The packages contain the WriteableBitmapEx binaries. All samples and the source code can be found in the repository.

A big thank you to all the contributors, bug reporters and users of the library who helped to shape this. You rock!

Changes

• Added lots of contributions including DrawLine with variable thickness, penning, improved anti-aliasing and Wu's anti-aliasing algorithm
• Added usage of CohenSutherland line clipping for DrawLineAa and DrawLine, etc.
• Added support for alpha blended filled shapes and adapted the FillSample for WPF
• Added FillPolygonsEvenOdd() which uses the even-odd algorithm to fill complex polygons with more than one closed outline like for the letter O
• Added AdjustBrightness(), AdjustContrast() and AdjustGamma() methods
• Added Gray() method which returns the gray scaled version the bitmap
• Fixed regression issue with alpha blending for Blit for non-WinRT
• Fixed bug in Blit Alpha code for WPF when source format is not pre-multiplied alpha
• Fixed bug #21778 where FromStream for WPF needs to be called inside Init scope
• Fixed issue with IndexOutOfRangeEx in DrawLine method
• Fixed Invalidate for Silverlight BitmapContext.Dispose
• Fixed many more reported issues
• ...

How to Encode and Save a WriteableBitmap with Windows WinRT

Windows WinRT 8.1 brought the support of the RenderTargetBitmap and the ability to render the visual tree of the UI into a bitmap. WriteableBitmapEx makes it even easier in the latest version and you might end up in a situation where you want to save a WriteableBitmap to a file or to a stream in general. For that the raw pixel array of the WriteableBitmap needs to be encoded into a common format like JPEG, PNG, etc.

Here's a code snippet how this can be achieved:

private static async Task SaveWriteableBitmapAsJpeg(WriteableBitmap bmp, string fileName)
{
   // Create file in Pictures library and write jpeg to it
   var outputFile = await KnownFolders.PicturesLibrary.CreateFileAsync(fileName, CreationCollisionOption.ReplaceExisting);
   using (var writeStream = await outputFile.OpenAsync(FileAccessMode.ReadWrite))
   {
      await EncodeWriteableBitmap(bmp, writeStream, BitmapEncoder.JpegEncoderId);
   }
   return outputFile;
}

private static async Task EncodeWriteableBitmap(WriteableBitmap bmp, IRandomAccessStream writeStream, Guid encoderId)
{         
   // Copy buffer to pixels
   byte[] pixels;
   using (var stream = bmp.PixelBuffer.AsStream())
   {
      pixels = new byte[(uint) stream.Length];
      await stream.ReadAsync(pixels, 0, pixels.Length);
   }

   // Encode pixels into stream
   var encoder = await BitmapEncoder.CreateAsync(encoderId, writeStream);
   encoder.SetPixelData(BitmapPixelFormat.Bgra8, BitmapAlphaMode.Premultiplied,
      (uint) bmp.PixelWidth, (uint) bmp.PixelHeight,
      96, 96, pixels);
   await encoder.FlushAsync();
}

It's all  pretty straightforward actually: The SaveWriteableBitmapAsJpeg creates a file in the user's pictures library and passes the file's stream and an BitmapEncoder ID on to the EncodeWriteableBitmap method which is doing the actual work. EncodeWriteableBitmap first copies the WriteableBitmap pixel buffer into a byte array, then creates the BitmapEncoder based on the file's stream and the desired BitmapEncoder ID, then sets the pixels and flushes all into the stream.
The BitmapEncoder class supports a couple of BitmapEncoder IDs out of the box like JPEG, PNG and more.

Easy Render! - WriteableBitmapEx now with Better Support for Win 8.1 RenderTargetBitmap

The lack of WriteableBitmap.Render in Windows WinRT 8.0 was quite an issue for many apps, but fortunately did WinRT 8.1 (re-)introduce the RenderTargetBitmap class which provides the functionality of rendering the visual tree of the UI to a bitmap. The new update of WriteableBitmapEx makes it even easier to use with a WriteableBitmap by introducing the FromPixelBuffer method.

WriteableBitmapEx is available for 4 platforms: Windows Phone 8 and 7, WPF, Silverlight and Windows Store WinRT .NET XAML 8 and 8.1.

You can download the binaries here or via the NuGet package. The packages contain the WriteableBitmapEx binaries. As usual all samples and the source code can be found in the repository.

How to use
The below code snippet shows how a part of the UI can be rendered into a WriteableBitmap via RenderTargetBitmap, how it can be modified and then finally presented back into the UI by using an Image control.

// Render some UI to a RenderTargetBitmap
var renderTargetBitmap = new RenderTargetBitmap();
await renderTargetBitmap.RenderAsync(Panel);
            
// Get the pixel buffer and copy it into a WriteableBitmap
var pixelBuffer = await renderTargetBitmap.GetPixelsAsync();
var width = renderTargetBitmap.PixelWidth;
var height = renderTargetBitmap.PixelHeight;
var wbmp = await new WriteableBitmap(1, 1).FromPixelBuffer(pixelBuffer, width, height);

// Modify the WriteableBitmap
wbmp.FillEllipse(10, 10, 256, 256, Colors.Salmon);
// ... More drawing including writeableBitmap.Blit(...) might go here

// Assign WriteableBitmap to an Image control to present it
ImgMirror.Source = wbmp;

Kinect and Leap Motion in Love

Natural User Interfaces are a trend since a few years and the development of new hardware technology for affordable prices helps to push that movement into the consumer market. The Kinect is one example, the soon-to-be-available Leap Motion is another one or the announced MYO device.

I'm one of the lucky people who applied and actually got a Leap Motion developer device before its release. I also have a Kinect for Windows. Both devices use computer vision with various sensors combined with artificial intelligence like machine learning for the object recognition. The Kinect for Windows recognizes skeletons with joints in a distance of  80 - 400 cm or 40 - 300 cm (Near Mode) which means the Kinect is perfect for the mid range distance but not for close PC interaction. The Leap Motion on the other hand is more for the close range and detects hands, fingers and pen-like objects very precisely. That's why I wanted to combine them and build a proof of concept hybrid solution that leverages both Kinect and Leap Motion to get the best of both worlds (close and mid distance).

In the video below I demo my proof of concept which is based on the Kinect for Windows SDK 1.7 and its Interactions and Controls components, plus the Leap Motion developer device and its beta SDK.
By the way, the Kinect for Windows SDK 1.7 is now publicly available and the bits are nothing less than awesome.




In case you are wondering about the infrared interference of the Kinect and Leap Motion. There's some, but I actually didn't notice any serious effect on the recognition capabilities of the Kinect nor the Leap.
Below is a picture of the Leap Motion as seen through the Kinect's infrared stream. The Leap Motion has three light sources but those are not very bright.

Some might say the Leap Motion is a competitor to the Kinect for Windows, I see it more like a nice addition to our developer toolset and the beginning of a story: Kinect ♥ Leap Motion.

Faster! - WriteableBitmapEx for Windows Phone 8 and WinRT Updated

The Windows Phone 8 SDK is now available and with that WriteableBitmapEx was updated too. The performance of the WinRT XAML version was also improved dramatically and an update is highly recommended.
WriteableBitmapEx is available for 4 platforms: Windows Phone 8 and 7, WPF, Silverlight and Windows Store WinRT .NET XAML.
You can download the binaries here or via the NuGet package. The packages contain the WriteableBitmapEx binaries. As usual all samples and the source code can be found in the repository.

Know Your Users - Windows 8 Store App System Info

This is just a quick a post to provide a little class for Windows 8 Store app development. The SystemInformation class gathers some useful information about the current system and can dump those as a string. I usually have such a class for all the platforms I work on and it's very helpful for logging and error analysis, but it also serves as a list of all available system information which are scattered in different APIs. The info can also be used to dynamically adapt the app, etc.

Here's the code I have so far, you can also download the complete class here.

public static async Task Dump(bool shouldDumpCompleteDeviceInfos = false)
{
   var builder = new StringBuilder();
   var packageId = Windows.ApplicationModel.Package.Current.Id;
   var clientDeviceInformation = new EasClientDeviceInformation();
    
   // Get hardware Id
   var token = HardwareIdentification.GetPackageSpecificToken(null);
   var stream = token.Id.AsStream();
   string hardwareId;
   using (var reader = new BinaryReader(stream))
   {
      var bytes = reader.ReadBytes((int)stream.Length);
      hardwareId = BitConverter.ToString(bytes);
   }

   builder.AppendLine("***** System Infos *****");
   builder.AppendLine();
#if DEBUG
   builder.AppendLine("DEBUG");
   builder.AppendLine();
#endif
   builder.AppendFormat("Time: {0}", DateTime.Now.ToUniversalTime().ToString("r"));
   builder.AppendLine();
   builder.AppendFormat("App Name: {0}", packageId.Name);
   builder.AppendLine();
   builder.AppendFormat("App Version: {0}.{1}.{2}.{3}", packageId.Version.Major, packageId.Version.Minor, packageId.Version.Build, packageId.Version.Revision);
   builder.AppendLine();
   builder.AppendFormat("App Publisher: {0}", packageId.Publisher);
   builder.AppendLine();
   builder.AppendFormat("Supported Package Architecture: {0}", packageId.Architecture);
   builder.AppendLine();
   builder.AppendFormat("Installed Location: {0}", Windows.ApplicationModel.Package.Current.InstalledLocation.Path);
   builder.AppendLine();
   builder.AppendFormat("Store App Id: {0}", CurrentApp.AppId);
   builder.AppendLine();
   if (CurrentApp.LicenseInformation.IsActive)
   {
      var listingInformation = await CurrentApp.LoadListingInformationAsync();
      builder.AppendFormat("Store Current Market: {0}", listingInformation.CurrentMarket);
      builder.AppendLine();
   }
   builder.AppendFormat("Culture: {0}", CultureInfo.CurrentCulture);
   builder.AppendLine();
   builder.AppendFormat("OS: {0}", clientDeviceInformation.OperatingSystem);
   builder.AppendLine(); 
   builder.AppendFormat("System Manufacturer: {0}", clientDeviceInformation.SystemManufacturer);
   builder.AppendLine();
   builder.AppendFormat("System Product Name: {0}", clientDeviceInformation.SystemProductName);
   builder.AppendLine();
   builder.AppendFormat("System Sku: {0}", clientDeviceInformation.SystemSku);
   builder.AppendLine();
   builder.AppendFormat("System Name: {0}", clientDeviceInformation.FriendlyName);
   builder.AppendLine();
   builder.AppendFormat("System ID: {0}", clientDeviceInformation.Id);
   builder.AppendLine();
   builder.AppendFormat("Hardware ID: {0}", hardwareId);
   builder.AppendLine();
   builder.AppendFormat("User Display Name: {0}", await UserInformation.GetDisplayNameAsync());
   builder.AppendLine();
   builder.AppendFormat("Window Bounds w x h: {0} x {1}", Window.Current.Bounds.Width, Window.Current.Bounds.Height);
   builder.AppendLine();
   builder.AppendFormat("Current Orientation: {0}", DisplayProperties.CurrentOrientation);
   builder.AppendLine();
   builder.AppendFormat("Native Orientation: {0}", DisplayProperties.NativeOrientation);
   builder.AppendLine();
   builder.AppendFormat("Logical DPI: {0}", DisplayProperties.LogicalDpi);
   builder.AppendLine();
   builder.AppendFormat("Resolution Scale: {0}", DisplayProperties.ResolutionScale);
   builder.AppendLine();
   builder.AppendFormat("Is Stereo Enabled: {0}", DisplayProperties.StereoEnabled);
   builder.AppendLine();
   builder.AppendFormat("Supports Keyboard: {0}", IsKeyboardPresent());
   builder.AppendLine();
   builder.AppendFormat("Supports Mouse: {0}", IsMousePresent());
   builder.AppendLine();
   builder.AppendFormat("Supports Touch (contacts): {0} ({1})", IsTouchPresent(), new TouchCapabilities().Contacts);
   builder.AppendLine();
   builder.AppendFormat("Is Network Available: {0}", NetworkInterface.GetIsNetworkAvailable());
   builder.AppendLine();
   builder.AppendFormat("Is Internet Connection Available: {0}", NetworkInformation.GetInternetConnectionProfile() != null);
   builder.AppendLine();
   builder.AppendFormat("Network Host Names: ");
   foreach (var hostName in NetworkInformation.GetHostNames())
   {
      builder.AppendFormat("{0} ({1}), ", hostName.DisplayName, hostName.Type);
   }
   builder.AppendLine();
   builder.AppendFormat("Current Memory Usage: {0:f3} MB", GC.GetTotalMemory(false) / 1024f / 1024f);
   builder.AppendLine();
   builder.AppendFormat("App Temp  Folder: {0}", ApplicationData.Current.TemporaryFolder.Path);
   builder.AppendLine();
   builder.AppendFormat("App Local Folder: {0}", ApplicationData.Current.LocalFolder.Path);
   builder.AppendLine();
   builder.AppendFormat("App Roam  Folder: {0}", ApplicationData.Current.RoamingFolder.Path);
   builder.AppendLine();
   builder.AppendLine();

   if (shouldDumpCompleteDeviceInfos)
   {
      var devInfos = await DeviceInformation.FindAllAsync();
      builder.AppendLine();
      builder.AppendLine("Complete Device Infos:");
      foreach (var devInfo in devInfos)
      {
         builder.AppendFormat("Name: {0} Id: {1} - Properties: ", devInfo.Name, devInfo.Id);
         foreach (var pair in devInfo.Properties)
         {
            builder.AppendFormat("{0} = {1}, ", pair.Key, pair.Value);
         }
         builder.AppendLine();
      }
   }

   return builder.ToString();
}

public static bool IsTouchPresent()
{
 return new TouchCapabilities().TouchPresent == 1;
}

public static bool IsMousePresent()
{
 return new MouseCapabilities().MousePresent == 1;
}

public static bool IsKeyboardPresent()
{
 return new KeyboardCapabilities().KeyboardPresent == 1;
}

On my system it provides the following info (anonymized):

***** System Infos *****

DEBUG

Time: Sun, 28 Oct 2012 07:51:11 GMT
App Name: MyApp
App Version: 1.0.0.5
App Publisher: CN=A8E2F0B1-4749-48AE-AE18-C7FFB5B30272
Supported Package Architecture: Neutral
Installed Location: D:\Development\MyApp\bin\Debug\AppX
Store App Id: 00000000-0000-0000-0000-000000000000
Culture: en-US
OS: WINDOWS
System Manufacturer: Dell Inc.
System Product Name: Precision M6600
System Sku: 
System Name: MYLAPTOP
System ID: 18a2e8c6-cc7d-8546-1e9e-56a12ffb32fd
Hardware ID: 03-00-D2-41-03-00-AA-72-08-00-EF-AD-05-AA-B6-4F-06-00-01-01-04-00-31-1B-04-00-0C-48-04-00-D2-55-04-00-D3-66-01-00-0E-D6-02-00-E4-7F-09-00-56-47
User Display Name: Rene Schulte
Window Bounds w x h: 1920 x 1080
Current Orientation: Landscape
Native Orientation: Landscape
Logical DPI: 96
Resolution Scale: Scale100Percent
Is Stereo Enabled: False
Supports Keyboard: True
Supports Mouse: True
Supports Touch (contacts): False (0)
Is Network Available: True
Is Internet Connection Available: True
Network Host Names: mylaptop (DomainName), mylaptop.local (DomainName), 169.254.85.85 (Ipv4), 192.168.2.148 (Ipv4), 
Current Memory Usage: 0.451 MB
App Temp  Folder: C:\Users\Rene\AppData\Local\Packages\MyApp\TempState
App Local Folder: C:\Users\Rene\AppData\Local\Packages\MyApp\LocalState
App Roam  Folder: C:\Users\Rene\AppData\Local\Packages\MyApp\RoamingState

If you know more system information Windows 8 APIs that listing is missing, please add a comment.

Update WriteableBitmapEx for WinRT RTM, WPF, Windows Phone and Silverlight

The RTM version of Windows 8 is now available and with that WriteableBitmapEx was updated too. WriteableBitmapEx is now available for 4 platforms: WPF, Silverlight, Silverlight for Windows Phone and Windows Store Style WinRT .NET.
You can download the binaries here or via the NuGet package. The packages contain the WriteableBitmapEx binaries. As usual all samples and the source code can be found in the repository.



Since the last WinRT release preview version, a couple of bugs were fixed and a new FromStrean method was added which loads an image stream into a WriteableBitmap. The project was also updated for the Windows 8 RTM version. Please read this blog post for more details about the WinRT version.

It's Alive! - WriteableBitmapEx 1.0 for WinRT Metro Style, WPF, Windows Phone and Silverlight

After a few preview versions, I'm happy to announce that the final version of WriteableBitmapEx 1.0 is now available.
A couple of weeks ago we added official WPF support and WinRT Metro Style support. With that WriteableBitmapEx is now available for 4 platforms: WPF, Silverlight, Silverlight for Windows Phone and Metro Style WinRT .NET.
You can download the binaries here or via the NuGet package. The packages contain the WriteableBitmapEx binaries. All samples and the source code can be found in the repository.


Since the last WinRT preview version, a new WinRT sample was added, a couple of bugs were fixed and a new FromStrean method was added which loads an image stream into a WriteableBitmap. The project was also updated for the Windows 8 Release Preview. Please read this blog post for more details (about the WinRT version).

One Bitmap to Rule Them All - WriteableBitmapEx for WinRT Metro Style

A couple of weeks ago we added official WPF support to  WriteableBitmapEx. Today I'm happy to announce that WriteableBitmapEx now also officially supports Windows 8 Metro Stlye WinRT .NET XAML. With that WriteableBitmapEx is now available for 4 platforms: WPF, Silverlight, Silverlight for Windows Phone and Metro Style WinRT .NET.
Although Direct2D is the best solution for fast 2D graphics with Windows 8 Metro Style, I think there are scenarios where the WriteableBitmapEx could be helpful, esp. when using C# with XAML. I also know that some devs were waiting for this to port their Windows Phone apps to Windows 8 Metro Style.

WinRT Differences
Unlike the Silverlight WriteableBitmap, the Metro Style WriteableBitmap doesn't provide the pixel data directly. Its IBuffer PixelBuffer property doesn't have an interface to get the color information. Fortunately there are a few C# extension methods available which provide the pixel data as byte array or stream in the BGRA pixel format. Yes, BGRA and not like all the other platforms supported by WriteableBitmapEx as ARGB. The BGRA format is mainly used by Direct2D, which might be the reason for this hidden, but important difference of the Metro Style WriteableBitmap.
The WriteableBitmapEx algorithms are written for the ARGB pixel format. Fortunately I was able to keep the details away from the library user by leveraging the BitmapContext concept we introduced with the WPF support. This approach makes it possible to share almost the same code for all 4 platforms without being cluttered with #if directives all over place.  Actually the most significant WinRT adaptation inside the WriteableBitmapEx methods was done in the FromContent method, which loads an image from the app content and provides it as WriteableBitmap. See this StackOverflow question I answered if you're interested in the details.
Nothing comes for free, but if the BitmapContext is used the right way, the performance hit won't be that much thanks to an internal reference counting WriteableBitmapEx' BitmapContext uses. No worries, you don't have to change all your WriteableBitmapEx calls, just wrap your calls in a simple using(writeableBmp.GetBitmapContext()) and you will only have one buffer conversion instead of one for each draw call.
It's really simple to use:

private void Draw()
{
   // Wrap updates in a GetContext call, to prevent invalidation overhead
   using (writeableBmp.GetBitmapContext())
   {
      writeableBmp.Clear();
      DrawPoints();
      DrawBeziers();
  
   } // Invalidates on exit of using block
}

private void DrawPoints()
{
   foreach (var p in points)
   {
      DrawPoint(p, Colors.Green, PointVisualSizeHalf);
   }
}

private void DrawPoint(ControlPoint p, Color color, int halfSizeOfPoint)
{
   var x1 = p.X - halfSizeOfPoint;
   var y1 = p.Y - halfSizeOfPoint;
   var x2 = p.X + halfSizeOfPoint;
   var y2 = p.Y + halfSizeOfPoint;
   writeableBmp.DrawRectangle(x1, y1, x2, y2, color);
}

private void DrawBeziers()
{
   if (points.Count > 3)
   {
      writeableBmp.DrawBeziers(GetPointArray(), Colors.Yellow);
   }
}

Screenshot WinRT Metro Style sample running in the simulator

All samples were tested with the new version, but due to the refactoring more testing is needed. Please test this version with your projects and report the bugs you encounter. You can download the binaries here. Note that this package only contains the WriteableBitmapEx binaries for Silverlight, Windows Phone, WinRT Metro Style .NET and WPF. All the samples can be found in the source code repository in the branch "WBX_1.0_BitmapContext". If all goes well, this branch will become the trunk and the 1.0 RTM in a few weeks.

WinMD / Windows Runtime Component
There's also a WinMD version available which makes it possible to consume the WriteableBitmapEx library from all the WinRT Metro Style projections, although only C# and C++ XAML make actually sense.
I had to move some parts and leave some functionality like the ForEach out, but it contains 99% of the library's features. Unfortunately the C++ sample I created crashes when the WriteableBitmapExWinMD library is loaded. So for now this WinMD version can be found in a separate branch "WBX_1.0_WinMD" in the source code repository and it won't be part of the trunk and release until it works with the sample. I'm a bit running out of time and don't know where to look for, since it seems all is wired up correctly and compiles fine. If you are a WinMD wizard and have a few minutes, I'd appreciate if you could look into the WinMD version.

Let me out - Facebook Logout in a Windows Phone App

A while ago I implemented the Facebook photo endpoint into my Windows Phone Pictures Lab app. The implementation of the login was quite straightforward thanks to OAuth 2.0. Only the logout was way harder than one might expect. This post describes how to logout from Facebook using the Facebook API.






In my Pictures Lab app you can edit photos, make them look awesome and then save or share those with your friends at Twitter or Facebook. The Windows Phone Mango API provides the ShareLinkTask and the ShareStatusTask which can be used by an app to share an URL or text using the social services the user has connected the device to. Unfortunately there's no built-in SharePhotoTask to share a photo using the services the user has already authorized. That's why I had to implement it in a custom way where the user has to authorize again. This blog post by my mate Nick Randolph describes very well how to login to Facebook from a Windows Phone app.

For some situations it might make sense to allow the user to logout from within the app. One might think this can't be hard and in most cases it's pretty easy. Logging out from Twitter is very easy for example. You just have to start the authorization process again. However, logging out from Facebook is way harder since they store a cookie and the WebBrowser control doesn't provide a way to clear the cookies, so just starting the authorization process again doesn't work.
One way to log out from Facebook uses a special Uri that contains a part of the access token which was queried during the app authorization process.

Here's the snippet I use in Pictures Lab to split the access token to get the session key which is then used to build the custom Uri:

public Uri GetLogoutUri(FacebookCredentials credentials)
{
   var sessionkey = ExtractSessionKeyFromAccessToken(credentials.AccessToken);
   var url = String.Format("http://facebook.com/logout.php?app_key={0}&session_key={1}&next={2}", EndpointData.FacebookAppId, sessionkey, EndpointData.FacebookLogoutCallbackUrl);
   return new Uri(url);
}

private static string ExtractSessionKeyFromAccessToken(string accessToken)
{
   if (!String.IsNullOrEmpty(accessToken))
   {
      var parts = accessToken.Split('|');
      if (parts.Length > 2)
      { 
         return parts[1];
      }
   }
   return String.Empty;
}

That logout Uri is then used to navigate the WebBrowser control to it which then correctly triggers the log out process.

Browser.Navigate(FacebookService.GetLogoutUri(EndpointData.Settings.Facebook));

That's it. You just have to know their trick. Hope this helps.

SLARToolkit Samples Updated

The samples of my open source Windows Phone and Silverlight Augmented Reality Toolkit were updated to the latest version of the WP 7.1 and Silverlight 5 SDKs.
Please note the changed security model in Silverlight 5, which is a big bummer. My Silverlight MVP friend Morten wrote a few true words about it here.
As usual you can find a list of the samples on the project site and also get the code there.

WriteableBitmapEx 1.0 Coming Soon, Test it Now!

A new version of the WriteableBitmapEx open source library has just been released, but that isn't the last release for this year. No, Andrew Burnett-Thompson and I refactored the library to make it easier portable and we added full WPF support. Andrew did most of the work since he needed the current WriteableBitmapEx library for one of his WPF projects. As a result of the refactoring, WriteableBitmapEx will have maintained support for WPF starting with version 1.0.
I'd have loved to add support for WinRT too, but unfortunately it seems that WinRT only supports streamed reading / writing of the pixel buffer at the moment. I will wait until Microsoft ships the Windows 8 beta early next year and see what they have in there. Many WriteableBitmapEx algorithms need random buffer index access and I don't want to waste my time with massive memory copying now. Who knows what else comes in the beta and it might be better to use a whole different approach for immediate rendering with Windows 8 and WinRT.

All samples were tested with the new version, but due to the massive refactoring more testing is needed. Please test the beta version with your projects and report any bugs you find. You can download the binaries here. Note that this package only contains the WriteableBitmapEx binaries for Silverlight, Windows Phone and WPF. All the samples can be found in the source code repository in the branch "WBX_1.0_BitmapContext". If all goes well this branch will become the trunk in a couple of weeks.

Windows Phone Sites Around the World

I recently released an update of my Windows Phone app Pictures Lab which brings some nice new features like effect combination, two Christmas and a New Year frame and most importantly 7 new languages. Pictures Lab 4.0 now supports 9 languages: English, German, Japanese, Russian, Dutch, French, Italian, Spanish, Portuguese. This was made possible by a group of awesome native-speaking translators: Alan Mendelevich, Takeshi Miyauchi, David Salazar, Joost van Schaik, Johan Peeters, Paolo Barone, Simone Chiaretta, Pedro Lamas and Quentin Calvez.


I also asked my translators if they know any local Windows Phone news sites / blogs. Below is a list of international and regional Windows Phone news sites we collected. Note, that those are primarily consumer sites read by consumers and not only for developers. This list could be useful if you plan to release a localized version of your app and want to promote it a bit. Most sites have a "Tip Us" or contact form and are mostly happy about new content to write posts about.

Forget this list! 
Head over to @ailon's awesome dedicated site: http://windowsphonesites.com

English

• http://wmpoweruser.com
• http://mobilitydigest.com
• http://www.wpcentral.com
• http://allaboutwindowsphone.com
• http://windowsphonegeek.com
• http://zomgitscj.com
• http://www.mykindofphone.com
• http://www.windowsphonemetro.com
• http://windowsphoneparent.com
• http://www.1800pocketpc.com
• http://pocketnow.com
• http://www.wp7connect.com
• http://www.windowsphonedaily.com
• http://www.wpsauce.com (India)
• http://ilovewindowsphone.in (India)
• http://www.windowsphonerocks.com

German

• http://wp7app.de
• http://worldofppc.de
• http://www.phoneseven.de
• http://wp7de.com
• http://www.windows-smartphones.de
• http://www.pocketpc.ch

Russian

• http://WP7Rocks.com
• http://WP7Forum.ru
• http://W7Phone.ru
• http://W7Ph.ru

Japanese

• http://nanapho.jp
• http://blogs.shintak.info
• http://blogs.msdn.com/b/aonishi

Dutch

• http://wp7.nl

Spanish

• http://wphone.es
• http://www.miwindowsphone.net
• http://www.windowsphoneforos.com
• http://wp7total.info
• http://www.xataka.com/moviles/windows-phone-7

Portuguese (Brazilian)

• http://windowsphonebrasil.com.br

Italian

• http://www.windowsphoneitaly.com
• http://www.plaffo.com
• http://www.wpmitalia.com
• http://www.windows7blog.it
• http://www.cellularemagazine.it
• http://www.tecnophone.it
• http://cellulariadhoc.blogosfere.it
• http://webmobile.blogosfere.it
• http://www.mobileblog.it
• http://mobile.hdblog.it
• http://www.hi-techitaly.com

French

• http://www.monwindowsphone.com

Danish

• http://www.windowsphonefan.dk

If you know more sites, please leave a comment and I'll update the list.

Telerik published a nice whitepaper with more resources about app promotion.

WriteableBitmapEx 0.9.8.5 Now Available

The WriteableBitmapEx open source library has come a long way since I created the CodePlex site in December 2009. A lot of features and the support for new platforms were added in subsequent releases. The package is also available via NuGet since this year.
The new release v0.9.8.5 was just made public. A few new features were added and many small, uncritical issues were fixed (see the list below). The binaries can be downloaded from here or via the NuGet package. Please note that this package only contains the WriteableBitmapEx binaries for Silverlight and Windows Phone. All the samples can be found in the source code repository.


Feature list version 0.9.8.5

• Added a Rotate method for arbitrary angles (RotateFree). Provided by montago.
• Added Nokola's anti-aliased line drawing implementation.
• Updated the Windows Phone project to WP 7.1 Mango.
• Added an extension code file for the Windows Phone specific extensions and added SaveToMediaLibrary extensions including support for saveToCameraRoll.
• Added an Invert method, which creates an inverted version of the input bitmap. This is useful for WP7 Theme-awareness checks using Application.Current.Resources["PhoneBackgroundBrush"].
• Added FromContent method, which provides an easy interface to load a WriteableBitmap from the content of the app.
• Added a static overload for the Resize method which takes the pixels array as argument.
• Optimized the DrawLine algorithm.
• Fixed some issues with DrawRectangle, FillRectangle, DrawEllipse, FillEllipse and DrawPolyline.
• Fixed a bug in the bilinear Resize method that appeared when the alpha value is zero.
• Fixed other minor issues.

Community Community Community!
Thanks to the community for constantly reporting bugs, suggesting new features and contributing code. That's exactly why open source software is just awesome.

Welcome to Zombieland, the Metro Style Land of WinRT and the Undead

Silverlight is dead! WPF is dead! .NET is dead! Hey, they didn't talk about SharePoint or SQL Server at the BUILD conference, those must be dead too. Welcome our new Metro-id overlords!
We read such FUD everywhere these days. Actually none of these technologies are dead for the next several years! And you'll probably agree if you know the facts and not the FUD. So here are my thoughts based only on the facts I got from watching BUILD sessions, reading posts that stick to the facts and not listening to people who obviously didn't inform themselves, but nevertheless spread FUD around.

What happened
Microsoft announced the new version of Windows at the BUILD conference and the new Windows 8 runtime called WinRT, which is used to develop Metro style Apps. Metro style Apps are primarily focused on consumers, designed touch first and therefore perfect for modern multi-touch devices like tablets.
The good ol' desktop is still there and the usual Windows applications are now called Desktop Apps.
There's a lot confusion out there at the moment and many think only Metro style Apps are the future. Actually both models can exist side-by-side and I'm sure the mainly used UI will be the classic desktop for the usual business client. Metro is for tablets, maybe later for the phone. Desktop Apps will still work better for the classic business PC scenario in an office.
After trying Windows 8 I don't see myself using Metro style Apps a lot on my PC when I work at the desk. However, I will love to use it when I'm hanging out on my couch with a tablet. The good news is, both models are supported by Windows 8 and therefore can run on one device, including ARM hardware. Awesome!

WinRT

First and foremost, .NET plays a significant role in both development models and is not only used for Desktop Apps. I guess the FUD comes from the architectural picture above, where .NET and Silverlight are only represented by a small box in the lower right corner. Of course Microsoft wants to push the new Metro style Apps, the WinRT model and wants to get web developers into the boat, so they adjusted the graphic and marketing message accordingly.
WinRT is actually a new native COM library, plus some extra infrastructure. Therefore an app developer has not to deal with the COM stuff directly, instead you get a thin / fast projection layer (binding) for each of the supported programming languages. This projection layer is automatically built using WinMD metadata and provides projections for JavaScript, .NET (C# / VB) or C / C++. The UI can be designed with XAML or HTML / CSS in case of JavaScript.
The rendering is completely done using DirectX 11.1 (Direct2D) which results in great performance. In Windows 8 the rendering job is finally fully executed by the right processor. This architecture makes it also possible to implement the complete UI just with DirectX, which will usually be done by games. At the moment it's not possible in the Windows 8 Developer Preview to mix a XAML app with DirectX, which doesn't make much sense since the XAML rendering is done by DirectX. Fortunately all hints that it'll be possible in a later version of Windows 8, maybe in the beta.

The below picture by Doug Seven is a way more accurate picture of the Windows 8 platform architecture.

There are a few good, unbiased posts about WinRT out there, which stick to the facts:
WinRT: An Object Orientated Replacement for Win32
WinRT, the C++ Component Extensions
WinRT demystified 
A bad picture is worth a thousand long discussions.
WinRT reference with all namespaces at the unbiased MSDN, where JaveScript is just another language one can use for Metro style Apps.

WinRT and .NET
From what I have seen so far, coding Metro style Apps using C# / .NET seems pretty straightforward if you've done Silverlight, WPF or esp. Windows Phone development before. The BCL used by .NET WinRT is not the full Desktop version of .NET 4.5, it's a reduced set similar to the Silverlight types.
The design of the native WinRT COM library was heavily influenced by .NET. You see it everywhere. Type names, Properties, Events... Even WinMD is the .NET assembly metadata format.
WinRT types map to .NET types and copying of data structures at the boundaries is avoided by the projection layer to get the best performance. Only two types need to be converted using built-in extension methods. The System.IO.Stream can't be mapped to the WinRT stream, so there's an extension method. A Byte[] to WinRT IBuffer conversion is the other extension method.
You can even write your own, custom WinRT components in C# without decorating the classes with ugly COM attributes. Those components are then automatically exposed to the other languages using the generic WinMD metadata. So you can write a component in C++ or in C# and use it from a JavaScript WinRT project. Pretty cool concept if you ask me.
Many WinRT classes look like their origin is .NET / Silverlight and the WinRT WriteableBitmap is also very similar to Silverlight's implementation. So expect a WinRT version of my open source WriteableBitmapEx library in a few weeks when I'm done with the Mango updates for all my Windows Phone apps. After that I will probably port / rewrite some of my WP7 apps for WinRT.

The lifecycle of a WinRT app should  be quite familiar for a WP7 developer, since it's similar to the WP 7.5 Mango Fast App Switching. The lifecycle states are: Running > Suspended in RAM > Terminated. Apps get an event for suspending, not for terminate, so the state has to be saved during suspending. Of course an app should only be resurrected from the tombstone state if the app was launched, not when resumed. Apps get 5s for suspending and need to launch within 15s. Unfortunately we don't know the reference machine where those values are measured. Probably the low end configuration.
By the way, the Windows Store will be the better version of the WP7 Marketplace. It will include In-App offers, time limited trials and a very nice dashboard with a lot of analytic capabilities and insights.
In general should a WP7 developer feel most familiar with WinRT. Many concepts made it into WinRT and were improved and actually cleaned up.
My Silverlight MVP friend Morten Nielsen started a blog post series about how to port Silverlight / WPF apps to WinRT.
You should also read this post: WinRT and .NET and watch the ton of great BUILD sessions.

Conclusion

I welcome the new possibilities and great performance we get in Windows 8 with the WinRT. I'm sure Windows 8 will be an awesome tablet OS.
XAML has become a first class citizen and .NET is now installed with Windows 8. Microsoft is also working on a next version of .NET. Version 4.5 of .NET will bring better performance for WPF's ItemsControl for example. Seems not very dead to me. In fact, a Silverlight / WPF / WP7 developer's knowledge of XAML and the Silverlight runtime is more valuable than ever before with WinRT.
Silverlight 5 is still in development and wasn't even released. We don't know if it will be the last version or if Silverlight 6 will see the light of the day. For now I'm quite happy with all the features of Silverlight 5 and we can develop a ton of applications for our customers for the next several years.

One should also not forget how long it will take until Windows 8 is finally out and reached a critical mass. A lot of machines out there still run Windows XP. Windows 7 is way better and I guess the transition to Windows 8 will take even longer. Windows 8 will probably mainly pushed by non-PC multi-touch consumer devices in the near future.

This flowchart by the Telerik guys sums it up pretty nicely.

So get yourself informed and start coding away. Don't give FUD a chance!

Cubelicious - Silverlight 5 + Balder + Physics + SLARToolkit Augmented Reality = Triple Win!

Two months ago I released a new Silverlight 5 sample for my open source Silverlight Augmented Reality Toolkit - SLARToolkit. It uses the new Silverlight 5 hardware accelerated 3D API. You can read more about the new Silverlight 5 XNA 3D API in this blog post.
This post here provides a new demo for SLARToolkit which uses the open source 3D engine Balder by my friend Einar Ingebrigsten. This demo also leverages the open source physics engine JigLibX my buddy Andy Beaulieu ported over to Silverlight. You can try the live sample if you have the Silverlight 5 beta installed or watch a video instead.

I actually spent most of the time on this project a couple of weeks ago. My good Silverlight MVP friend Einar Ingebrigtsen used it in his talk at The Gathering 2011. Now I finally had a bit time to finish the demo, make a video and this blog post.

The SLARToolkit project description from the CodePlex site:

SLARToolkit is a flexible Augmented Reality library for Silverlight with the aim to make real time Augmented Reality applications with Silverlight as easy and fast as possible. It can be used with Silverlight's Webcam API or with any other CaptureSource or a WriteableBitmap. SLARTookit is based on the established NyARToolkit and ARToolkit. 

Live

A webcam and at least the Silverlight 5 beta runtime must be installed to run the sample. It's available here. Alternatively there is also a video of the new sample embedded below.

If you want to try it yourself you need do download the SLAR and / or L marker, print them and hold them in front of the camera. The marker(s) should be printed non-scaled at the original size (80 x 80 mm) and centered for a small white border. As an alternative it's also possible to open a marker file on a mobile device and to use the device's screen as marker. Also make sure the camera is set up properly and the scene is illuminated well without hard shadows. See the SLARToolkit Markers documentation for more details.

Open the sample in a new page.

Simply press the "Start Cam" Button to start the webcam. The properties of the particle system can  be changed with Sliders. The "Flip x-axis" Checkbox can be used to flip the video (the webcam output is mirror-reversed by default). 

If you click the "Start Cam" Button for the first time you need to give your permission for the capturing. This application uses the default Silverlight capture device. You can specify the video and audio devices that are used by default with the Silverlight Configuration. Just press the right mouse button over the application, click "Silverlight" in the context menu and select the "Webcam / Mic" tab to set them.

Video

I've recorded a short video of the new sample with Expression Encoder's Screen Capture feature. Please keep in mind that the screen recording software eats up a lot of resources while recording and that the actual frame rate is even better. The video is also available at YouTube.

Background music is Lullaby by _ghost

This demo shows how the new Silverlight 5 3D API, the Balder engine and the JigLibX physics library can be used to augment the reality with the help of SLARToolkit.

How it works

This sample uses the webcam video stream which fills a Rectangle shape, the video stream is also constantly captured and fed to the SLARToolkit BitmapMarkerDetector to detect the markers. The detection result contains a transformation matrix for each found marker which is then used to apply a global transformation to the cubes and the plane.
I implemented a particle system with a flexible directed emitter which can be controlled through various properties. The particle system is quite generic and can be used for all kinds of particles (3D objects). The particle collision detection and resolving is based on rigid body physics that was implemented with the help of the JigLibX library my Silverlight MVP buddy Andy Beaulieu ported over to Silverlight.
The rendering and the model loading is done by the 3D engine Balder. It's a fantastic open source engine by Einar Ingebrigtsen. You just need to write a couple lines of XAML and you're good to go. This sample only uses a simple cube model, but Balder has built-in model loaders to load complex 3D models and Einar provides a big sample library. He also brought the engine to a few more platforms like Windows Phone 7, OpenGL and has even a neat software rendering fallback. Read his blog post here.
As part of this sample I needed some vector and quaternion methods which were missing in Balder. I contributed those and the generic particle system to the Balder project. Feel free to use the particle system and the other methods in your Balder projects.

Download it, build your app and augment your reality

The open source SLARToolkit library and all samples are hosted at CodePlex. If you have any comments, questions or suggestions don't hesitate and write a comment, use the Issue Tracker on the CodePlex site or contact me via any other media.
Have fun with the library and please keep me updated if you use it anywhere so I can put a link on the project site.